(Sorry, I wasn't clear about what I meant.)

I didn't refer to factual threats. I'm not talking about the What, but about the How.
Of course, Fredo had become a threat in GF2. And the Catholic church in GF3. But in cinematographic terms they don't scare us, the audience. Yes, Sollozzo was a thug with little power. But compare the radiation of Al Lettieri in the restaurant scene with that of Peter Donat as Questadt.
What I'm talking about is how the danger is being portrayed and how it transmits to the audience. Who's ever been scared of Gilday? Who was not scared of Brasi?